Device for cleaning air conduits

ABSTRACT

Device to clean air ducts which, as it includes a header connected to a compressed air generator by means of a supply hose, is characterised because the header has a front part ( 5 ) which can be connected in an adjustable fashion, to a back part ( 4 ) provided with many compressed air outlets formed by flexible bands ( 6 ) which make random movements owing to the reaction forces originated by the compressed air outlet through them, and which lash the walls of the duct.

OBJECT OF THE INVENTION

This invention refers to a device to clean air ducts, which consists ofa header which is inserted In the duct to be cleaned, and which isconnected by means of a supply hose, to a compressed air generator. Theheader is provided with a front part with an impact cushioning system,and a back part connected to the front and provided with compressed airoutlets composed of flexible bands which move during the output of thecompressed air, which significantly improves the effective cleaning ofthe inside surface of the duct, including recesses, corners and areas ofdifficult access.

BACKGROUND TO THE INVENTION

As a background to the invention, different devices with the samecleaning purpose as this invention, can be mentioned. The EuropeanPatent E90850157 includes generating a major vacuum inside the duct tobe cleaned, using an air current produced to move a cleaning element,such as a brush, inside the duct.

Patent E91905065 includes the use of a cleaning device connected, bymeans of a supply hose, to a compressed air source. This device consistsof an annular groove through which the compressed air used to clean theduct, is projected, and at the same time producing reaction forces whichare used to move the device inside the duct.

Patent E9197477 also includes a cleaning element connected by means of aduct, to a compressed air source. The element has one or more openingsin the shape of nozzles, directed backwards. The cleaning elements havean annular groove-shaped nozzle, through which compressed air isdischarged to clean the walls of the duct.

Similarly to the previous two, Patent WO 9324246 consists of a ductwhich connects a compressed air source to a spherical body provided withoutlets for the compressed air, directed towards the back, so that theduct is cleaned at the same time as the body advances.

These devices include, therefore, a cleaning element which is connectedby a supply hose, to a compressed air source. This cleaning element hascompressed air outlets, which simultaneously clean the duct and move theelement forward.

These devices have different problems; when the cleaning element isoperating, movements are abrupt and uncontrolled, owing to the reactionforces produced by the outlet of compressed air, causing the element tocontinuously knock against the walls of the duct being cleaned andleading to damage. Also, when these cleaning elements move forward in anuncontrolled fashion, it is possible that corners and recesses wherecompressed air is not sufficient, may not be cleaned properly. Finally,the diameter, the section or the upward downward or zigzag lay-out ofthe duct are features which, separately or together prevent thesecurrent methods of cleaning from being used, meaning that it isnecessary to have several different types of methods or leave lengths ofduct uncleaned.

DESCRIPTION OF THE INVENTION

The device of this Invention consists of a header which is insertedinside the duct to be cleaned, and connected by means of a supply hoseto a compressed air generator. This header consists of two parts, afront part and a back part, which are held together by means of athread. Many flexible bands are connected to the back part, throughwhich all or part of the compressed air emerges.

The front part consists of a low density soft body and hard body, with adiameter greater than all the components of the header, in order tocushion possible knocks of the header against the walls of the duct,preventing damage both to these walls and to the header.

The thread which connects the front to the back part can be a screw typewith nut, in which case, the soft body and the hard body are bore-holed,so that the screw passes through the hole to the rear part, which holdsthe socket of the nut. The screw and ring are loose parts, or they canbe placed in the back of the front part and capped in a cavitycoinciding with the front surface of the back part.

The coupling of the two main parts, up until now called the front andthe back, is such that the distance between them can be adjusted, sothat if they are completely joined, all the compressed air has to go outthrough the bands, but if a distance is left, adjusted on unscrewing thefront part if it can be unscrewed, or through the planned manufacture ofthe hard body of the front part when both main parts are joined by screwand nut, the compressed air will also go out through this circulargroove. The curtain of air formed when the compressed air goes outthrough the circular groove, means that the bands moving at random, willnever be in front of the header as they will not be able to crossthrough the curtain, and in some types of cleaning, this is an extraadvantage.

The compressed air enters the unit of the two parts through the backpart, which has a tubular tab at the back to connect the hose connectedto the compressed air generator. The inside hole of the tubular tab isprolonged to the front surface of this back part, and from there it isdistributed to be ejected through the bands or through the groove leftbetween the two main parts.

This back part also has many holes in the front, which extend to theback surface of the back part. Soft and flexible bands are attached tothese holes, which are therefore directed towards the back of theheader.

The reaction force caused by the discharge of compressed air through thebands, makes them move at random, which together with the fact that thelength of these bands is adjusted to the diameter of the duct, causesthem to lash on the layers of dirt deposited on the walls of the ductand to ensure deep cleansing of the duct, which up until now wasimpossible, as when the bands lash against the walls, they peel off thedirt which is compacted against the wall and which cannot be cleanedwith a jet of compressed air alone. As the bands are flexible and soft,they do not cause damage to the duct when they lash against the walls.

DESCRIPTION OF THE DRAWINGS

FIG. 1: Vertical section of a header with bands and open annular groove.

FIG. 2: Breakdown of parts of the header with bands, according to FIG.1.

FIG. 3: Section of the back part of the header with bands according toFIG. 1.

FIG. 4: Section of the two parts forming the other header with bands.

FIG. 5: Vertical section of the header according to FIG. 4 with closedannular groove.

FIG. 6: Vertical section of the device which is the object of thisinvention while an air-conditioning duct is being cleaned, showing theannual outlet of the header in the open position and the duct to becleaned vertically cross-sectioned.

Parts indicated:

1. Header.

2. Duct to be cleaned.

3. Compressed air hose.

4. Back part of header 1.

5. Front part of header 1.

6. Flexible band.

7. Annular groove between the front and back parts.

8. Hard body of the front part.

9. Air curtain formed by groove 7.

41. Tubular tab of the back part.

42. Base of nut to hold the front part to the back.

43. Compressed air distributor cavity inside header 1.

44. Outlets for compressed air.

45. Conical trunk surface of the back part 4.

51. Soft body of the front part.

52. Threaded tab of the hard body 8 if there is no screw 63.

53. Inside hole of tab 52 through which the compressed air passes.

54. Compressed air inlets to cavity 43.

55. Conical trunk surface of the hard body 8.

62. Screw ring.

63. Fastening screw of front part to the back.

72. Countersunk extension of band 6.

81. Opening through which the screw passes to join the front part to theback.

82. Teeth to fix the opening of the circular groove 7.

90. Compressed air inlet to the header.

91. Compressed air outlet through the bands.

Detailed Description of the Invention

As it can be observed in the above indicated drawings, the deviceconsists of a header (1) connected to a compressed air generator bymeans of a hose (3). The header (1) consists of a back part (4)connected to the hose (3), a front part (5) fixed to part (4) and softand flexible bands of any length (6) which are joined to part (4) anddirected towards the back of the header. The bands (6) make randommovements and lash against the dirt deposited on the inside wall of theduct.

The rear part (4) is connected to the hose (3) by means of a tubular tab(41) the inner hole of which is prolonged to holes (54), which lead tocavity (43), from where the compressed air will go out to the ductthrough the groove (7) and through the bands (6).

The front part 5 is connected to the back 4 by means of a screw (63),with ring (62) which is inserted in the base (42) or by a threaded part(42) which can be inserted in the base (42).

Part (4) also has holes (44) in the cavity (43). Bands (6) are connectedto these holes (44) by flaring one of its ends, with the band passingthrough the hole, and letting the flared length (72) act as aself-adjusted stop precisely by the compressed air, or they areconnected by a so-called quick connection pneumatic hose, which clampsthe tube.

The purpose of the soft body (51) is to dampen possible knocks of theheader (1) against the duct walls (2) during the cleaning operation.

The threaded tab (52) which is connected to the threaded portion (42) ofpart (4) has an inside cavity (53) where the compressed air goes afterbeing introduced in the header through the hose (2). It also has holes(54) through which the compressed air passes to cavity (43), whichdistributes the compressed air outlet through the bands (6) and thegroove (7).

If parts (4 and 5) are partially threaded, an annular groove (7) will beformed which is an additional outlet of compressed air.

The width of the annular groove (7) formed between the conical trunksurfaces (45 and 55) is adjusted by means of screwing the parts (4 and5) to a greater or lesser extent, if there is a tab (52), or by changingthe hard body (8) for another with teeth (82) of a different height.

Depending on the lay-out and features of the duct (2), the annulargroove (7) is adjusted, because the variations in the proportion ofcompressed air through the bands (6) and the groove (7) causesconsiderably different displacement, swinging or lashing movements ofthe header and its bands. The curtain of air (9) will prevent the bandsfrom entering the header.

What is claimed is:
 1. Device to clean air ducts comprising a header (1)connected to a compressed air generator by a supply hose wherein theheader has a front part (5) adjustably connected to a back part (4) toform annular groove (7) therebetween having a multitude of compressedair outlets, and a plurality of flexible bands (6) attached to theoutlets for transmitting compressed air therethrough, whereby thecompressed air causes the bands (6) to move to lash the walls of theducts.
 2. Device, according to claim 1 wherein the back part (4) has atubular tab (41) for connection to a supply hose (3).
 3. Device,according to claim 2 wherein the tubular tab has an inner hole that (41)is provided with a threaded portion (42) and a cavity (43) in order todistribute the compressed air through outlets (44) and (7).
 4. Device,according to claim 3 wherein the bands (6) are connected to holes (44)formed in part (4).
 5. Device according to claim 4 wherein the frontpart of the header (1) includes body (51) to dampen possible knocks ofthe header (1) against the walls of the duct (2) to be cleaned. 6.Device according to claim 1 wherein parts (4 and 5) form oppositeconical trunk surfaces (45 and 55), between which a chamber (43) isformed.
 7. Device, according to claim 6 wherein the back part (4) hasoutlets (54) to enable flow of compressed air towards chamber (43). 8.The device of claim 6 wherein parts (4 and 5) are spaced apart by teeth(82) to form annular groove (7).
 9. The device of claim 6 wherein parts(4 and 5) are threadedly connected to enable adjustment of the width ofannular groove (7).